In addition to components essential for the washing process, such as surfactants and builder materials, detergents generally contain further ingredients that can be grouped together under the term of washing auxiliaries and thus comprise various groups of active substances, such as foam regulators, graying inhibitors, bleaching agents, bleach activators, and enzymes. Such auxiliaries also include substances that are intended to prevent dyed textiles from having a changed color appearance after washing. This change in color appearance of washed, i.e., clean textiles may be due to, on the one hand, dye components being removed from the textile by the washing process (“fading”), and, on the other hand, dyes dissolving out from textiles of a different color being deposited on the textile (“discoloration”). The discoloration aspect can also play a role in the case of undyed laundry items when these are washed together with colored laundry items. In order to prevent these undesired side effects of removing dirt from textiles by treatment with aqueous systems typically containing surfactants, detergents, especially when they are provided as so-called color detergents for washing colored textiles, contain active ingredients that are intended to stop the dissolution of dyes from the textile or at least to prevent the deposition of dissolved-out dyes present in the washing liquor onto textiles. Many of the typically used polymers have such a high affinity for dyes that they draw them to a greater extent from the dyed fiber, such that greater color losses occur.
Dye transfer-preventing polyvinylpyrrolidones with molecular weights of 15,000 g/mol to 50,000 g/mol are known from the European patent application EP 0 262 897 and those with molecular weights over 1,000,000 g/mol from the international patent application WO 95/06098. The N-vinylimidazole/N-vinylpyrrolidone copolymers known from the German patent application DE 28 14 287 or DE 38 03 630 or the international patent applications WO 94/10281, WO 94/26796, WO 95/03388, and WO 95/03382, polyvinyloxazolidones known from the German patent application DE 28 14 329, the copolymers based on vinyl monomers and carboxylic acid amides known from the European patent application EP 610 846, pyrrolidone group-containing polyesters and polyamides known from the international patent application WO 95/09194, the grafted polyamidoamines and polyethylenimines known from the international patent application WO 94/29422, the polymers with amide groups from secondary amines known from the German patent application DE 43 28 254, and the polyamine-N-oxide polymers known from the international patent application WO 94/02579 or the European patent application EP 0 135 217 have also been proposed as dye transfer-preventing active substances.
It was now found surprisingly that certain polymers, defined below, lead to unexpectedly high color transfer inhibitions when used in detergents if the polymerization for producing the polymers is carried out in the presence of a dye.
Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.